1. Field of the Invention
The present invention relates to a solid-state image pickup device.
2. Description of the Related Art
Japanese Patent Laid-Open No. 2002-33469 describes a back surface incident type of solid-state image pickup device. In the solid-state image pickup device, light incident on the back surface of a semiconductor substrate from an object is photoelectrically converted inside the semiconductor substrate. Electric charges produced by the conversion are received by a light receiving unit to image the object.
Japanese Patent Laid-Open No. 2000-252452 and Japanese Patent Laid-Open No. 03-148172 in addition to Japanese Patent Laid-Open No. 2002-33469 are known as a prior art document related to the present invention.
The present inventor has found that the above solid-state image pickup device had the following problems to be solved. That is to say, in the above solid-state image pickup device, stray light may enter a semiconductor substrate on which a light receiving unit is provided from the face (surface) on the side opposite to the back surface being an imaging surface. Stray light entering the semiconductor substrate generates a false signal, degrading a pickup image.